The search for extraterrestrial intelligence — known as SETI — got a boost in 2015, when philanthropist Yuri Milner announced plans to inject up to $100 million into the field over the next decade. His cash is funding a project called Breakthrough Listen, which plans to survey the 1 million closest stars to us and 100 nearby galaxies, using advanced telescopes and a lot of computational power. But what exactly are those telescopes looking for? Andrew Siemion, scientific director of the Breakthrough Listen project, says it all comes down to electromagnetic signals. “Basically, what we look for in Breakthrough Listen, and really in any SETI experiment, is the kind of electromagnetic emission that we know can only arise from technology,” he explains. As Siemion explains, the Breakthrough Listen program uses both radio and optical telescopes in its search. “And we're also looking at some infrared and high-energy observatories, as well,” he says. It’s all in the hopes of picking up some sli
